Alleviating contrivances for silos, drying shafts and the like



y 1960 F. G. H. LAMKE 2,936,084

ALLEVIATING CONTRIVANCES FOR SILOS, DRYING SHAFTS AND THE LIKE FiledApril 1, 1957 v 3 Sheets-Sheet 1 F/GZ May 10, 1960 F. e. H. LAMKE2,936,084

ALLEVIATING CONTRIVANCES FOR SILOS, DRYING SHAFTS AND'THE LIKE FiledApril 1, 1957 3 Sheets-Sheet 2 y 1960 F. G. H. LAMKE 2,936,084

ALLEVI TI F/QS W 7L 1 4; 4 :1

-- ALLEVIATING CONTRIVANCES non SIL DRYINGSHAFISANDTHELIKE Gustaf HugoLamke, Stockholm, Sweden Application'April'1,'19$7, Serial No. 650,039

. 1- Claim.; 01. 214-17 r fl he present invention relates, to silos,drying shafts and the like, and more particularly to contrivances fortaking otherwise contained in 1 such shafts;

[The main object of the invention is to provide an alcated, at thebottom of the; silo or shaft. The upper side) of a beam of the knownkind has the form of two planes disposed at right angles to one another,and the space between two;,adj.acfent .be'ams' will thus vary in. amanner such that the free cross section of the shaftis reduced.

Thus, the material passing between the beams fromthe plane through thetop to the lower edge'of the beams will have to} move continuouslydecreasing spaces, "and this restriction of-the free cross sectioncauses angeven sinking of the material passing down the shaft and maycause the formation ofabridges and other disadvantages. It ,suchdisadvantage, in the first place, that should be' r'e'moved by the"present invention? A further object of the invention is to provide acombination of gratings capable of surely taking up the load of thecontents of relatively high silos, shafts and the like.

A still further object of the invention is to provide a contrivance fortaking up the load substantially in the lower portion of a shaft torelieve underlying means such as discharging means from the load ofmaterials of any kind consisting of grains or particles of a mostvarying size, and particularly material in ground condition.

A further object of the invention is to provide gratings for shaftswhich immaterially restrict the free cross section of the shaft.

According to the invention the contrivance comprises a gratingofinclined plates or the like extending transversely through the shaft,said plates being so arranged that the space between an arbitrary pairof adjacent plates has a constant or nearly constant cross section, or across section possibly flaring in the direction of movement of thematerial passing between said plates. Material passing from the upperedge of such a row to the lower edge thereof consequently moves at auniform velocity in the various spaces between the plates, inasmuchas-the free cross section is constant, and the invention thereforeinvolves the solution of the problem of attaining an even United StatesPatent 0 I i I. v H v I of one' 'and'the saniehorizontal sectiontheshaft."

2,936,084 P a tented May 1Q, 9

If all plates in the horizontal portion of the'shaft, wherein thegrating is located, are straight and extend in parallel to each other,the load of the superimposed material will give birth to forces'on theplates that have horizontal componentsdirected in the same direction.These' forces consequently tend to displace the plates horizontallytoward one side of the shaft. To prevent this, the-plates located on oneside of a'middle plane may 0 slope in the one direction to thehorizontal plane, while the plates locatedon the other side slope in theopposite direction,- the angles of inclination being then in bothup theload ofgranular-or powdered materials stored or 7 cases preferably equalnumerically, so that the horizontal component of theforces acting on oneside of said middle ponent of the forces acting on the other side.

Further features of the invention will appear from the followingdescription of a few forms of embodiment illustrated in the accompanyingdrawings. Fig. 1 shows a" vertical central section through a portion ofa shaft provided with .an alleviating contrivance according to theinvention, and Fig. 2 shows on a larger scale and in vertical projectionafew plates comprised in said contrivance.- Fig. 3 shows, in thesamemanner as Fig. l, asecon'd' embodiment of the invention, and Fig.4 showsa corresponding: horizontal projection with the upper gratingpartlyremoved. Figs. 5 and 6 show a third embodiment corresponding horizontalhaving the. alleviating contrivance arranged therein. In"

the embodiment according to Figs. l and 2, said contrivanc'e' consistsof two rows of plates located above one another, each of saidrows'forming a grating. Two arbitrary zadjacentplates 2, 3 in the uppergrating extend r irraparallel to each-other, so that a passage 4 is anduniform sinking of the material in the shaft. If

the shaft is provided with such inclined plates evenly distributed alongthe whole of its cross section, a uniform discharge of the material inthe lower opening of the formed between: them, saidpa'ssage broadlytaking the form of a 'parallelo'graminthe transverse vertical sectionshown. The free passage section within each row of such parallel platesis consequently constant from the upper edge 5 of the plates counted tothe lower edge 6. The plates extend in each horizontal grating inparallel to one another and bridgethe whole cross section of the shaft.

It is of importance that the upper edge of one plate of a pair ofarbitrary adjacent plates projects past the lower edge of the otherplate in the pair, that is to say, in a manner such that the projectionsof the plates on a horizontal plane overlap. Otherwise, the material inthe shaft could pass between the plates without being guided by thelatter, whereby the sinking of the material in the shaft could becomeirregular.

The plates take up the load from the superimposed material in the shaft,which at every individual plate may be represented by a force k actingon the upper side of the plate and directed at right angles thereto. Byreason of the inclination of the plate, said force tends to displace theplate not only downwardly but sideways as well. Asshown in Fig. 1, theplates, such as the plates 2, 3, located in the upper row on one side ofa middle plane of the shaft are inclined in one direction to thehorizontal plane, while the plates 7, 8 located on the other side ofsaid diagonal plane slope in the opposite direction. In both cases, theangle of inclination v is numerically the same, for which reason thehorizontal component h of the'forces k, which on account of the load ofthe contents of the shaft on the plates act on one side of the diagonalplane, is balanced by the horizontal component h of the forces k actingon the other side. The sloping plates are kept together by verticalplates 9 extending at rightangles to them, and these latter plates maybe anchored with their ends in opposite walls of the shaft. The ends ofthe plates may also be anchored in the shaft wall or in-ja frame 9.extending:a'll' around. The frame forms together with the sloping andvertical plates a grating which covers the cross section of the shaft. v

In' the construction according to Fig. 1, the plates '10, 1 1 of thelower grating slope in a direction opposed to that of the plates in theupper grating, but the longitudinal directions of the plates of the twogratings parallel each other. In this construction the lower plate edgesof the: upper grating may be located right above the. upper edges of thelower grating, but the downflow of the material between the plates isfacilitated,.if there is a small displacement.

The plates are arranged with approxiz surfaces. They are kepttogether byradial bracingplates mately the same pitch in the grating located aboveone another, but the-plates of the one grating are displaced by afraction of the pitch of the plates in the other grating. This iselucidated in Fig. 2, where the :pitchof the plates is denoted by a andthe plates 10, 110i the lower row are displaced by %a relatively to theplates 2, 3 of the upper row.

Figs. 34 show an embodiment, wherein two horizontal gratings 12, 14above one another the plates of the upper grating 12 extend with theirlongitudinal direction at right; angles to the plates of the lowergrating 14. Here'- by afurther distribution of the load is obtained.Both in the upper and in the lower grating the plates are inclined onone side of the middle'plane in a' direction opposed to that of theplates on the other side, whereby the resultant of the horizontalcomponents of the load on the various plates becomes equal to zero.

It should be noted that the shaftwall projects forwardly 17, at leastsome of which extend into'acentral conical member 18. This member may beconnected to a supporting spider 19 through a central rod 20 The spideris located at a distance above the grating. H

What I claim is:

A granular material load supporting apparatus comprising a cylindricalshaft having vertical walls, a horizontal grating traversing said shaftintermediate the upper and lower ends thereof, said grating consistingof a central conical member,-a' plurality of radially-spaced circularplates concentrically mounted about said central conical member andsloping. radially-outwardly front their top edges to their bottom edges,one of two adjacent plates having itsftop edge extending horizontallypast the lower edge of the other plate so that the projectionsof theplates on a horizontal plane will overlap, any" two plates formingtherebetween a space having a constant crosssection, andradially-arranged bracing plates connecting said circular plates tosaid-central conical member; spider means in said shaft above saidgrating; and means connecting the central conical portion of saidgrating to said spider means, said shaft having ahorizonta'lcross-sectional area below said grating which is at least as great asthe horizontal cross-sectional area above the grating;

References Cited in the file of this patent" UNITED STATES PATENTSs79,273 Kinealy Feb. 18. 1908 1,906,408 Persons May 2, 1933;

2,783,898 Ardern et all, Mar. 5, -7"

2,8 54,155 Payne Sept. 30, 1958 it FOREIGN PATENTS I 487,982 Canada Nov.11', 19 52" mama.

